Apparatus for treating metal strips



Feb. 16, 1943. R. H. GORDON ETAL APPARATUS FOR TREATING METAL STRIPS 3Sheets-Sht 1 Filed Feb. 15, 1940 11v VENTORS aribz F0};2"Z 7% 7. 7E0%e."

I %\ATTORNE Feb. 16, 1943. R. H. GORDON EIAL APPARATUS FOR TREATINGMETAL STRIPS Filed Feb. 15, 1940 1 5 Sheets-Sheet 2 4? Z INVgNTO/E E. 0er Fag F 16. V Wagmiys.

Feb. 16, 1943.

R. H. GORDON ETAL ,3 1,616

APPARATUS FOR TREATING METAL STRIPS s sheets-she t 3 Filed Feb. 15, 1940[N VE N T0195. ar i'a )7, 7, 7'dofe. y %\ATTORNEY$ Patented Feb. 16,1943 UNITED STATES PATENT OFFICE 2,311,616 APPARATUS Fortrnrarmo METALs'rairs Robert H. Gordon, Detroit, Mlcla, and Roy P. 'looke, Butler, Pa,assignors to The American Rolling Mill Company, Mlddietown, Ohio, acorporation of Ohio Application February 15, 1940, Serial No. 319,114

a 4 Claims. (Cl. 266-43) The present invention relates to improvedapparatus for processing strip steel, and particularly relates toimproved apparatus or applying rust-proofing solution to such stripsteel.-

It has been the practice in strip steel mills to store the strips in theform of coils outside of the mills where such coils are exposed to theelements with the result that they become rusted.

One of the primary objects of the present invention is to treat thesurface of strip steel so that it may be stored outside in coils andwill not rust when exposed to the elements.

Another object of the invention is to provide an apparatus by whichstrip steel may be continuously cleaned and thereafter treated toproprovision of means for keeping the strip moist until it enters thecoating bath,,whereby it is insured that the coating will be evenlydistributed over the strip.

Another object of the invention is the provision of mechanism whichinsures that the strip, upon its emergence from the coating bath, willnot carry along an excess of the coating fluid, whereby streaking andimevenness in the thickness of the coating is eliminated.

Another object of the invention is the provision of means whereby therust-proof coating SQlution duce coatings on the surfaces thereof torender such surfaces rust-proof.

Another object is to provide an improved dry- Y ing oven whereby thestrip steel may be efliciently subjected to heat after the rust-proofingsolution has been applied thereto in order to quickly dry j the same.

Another object of the invention is to provide an improved arrangement ofa. cleaning bath, a rinse, a bath of rust-proofing solutions, a dryingoven and means for continuously carrying a strip of steel through theseelements so that the surfaces of the strip may be rapidly andeconomically rust-prooted.

Another object of the invention is to provide an improved arrangement ofa cleaning bath, a rinse, a pretreating or flash bath, a. rinse, a bathof rust-proofing solution, a drying oven and means for continuouslycarrying a strip of steel through these elements so that the surfaces ofthe strip;

may be rapidly and economically rust-proofed.

Another object of the invention is to provide a machine for carrying outa'coating process of the nature above discussed, in which the successiveoperations are carried out upon the strip automatically and continuouslywithout the intervention of human hands.

. Another object of the invention is the provision of an apparatus asabove outlined in which the diilerent variable factors involved, such asthe treatment times in the various successive steps, may be closelycontrolled, to the end of producing a perfectly coated strip.

Another object of the invention is to provide an arrangement, wherebyexcess so lution is rinsed of! the strip immediately upon its emergencefrom the pretreating bath in order to avoid drying of such excesssolution upon the strip. I A further object ofthe invention involves theon the strip is dried as rapidly as possible and prior to contact of thestrip (after leaving the coating solution and after excess solution isremoved) with any conveying means.

A further object of the invention resides in the arrangement of theelements whereby the strip, after it issues from the last bath, is driedbefore it is engaged by any of the conveying means within a baking oven,whereby the coating is not in- Jared in any way by such engagement.

Another object of the invention is the provision of means whereby theprocessed strip istreated prior to its coiling so that such strip andthe coating thereon will not become injured by the subsequent coilingoperation.

A further object of the invention is the provision of cooling means solocated that as the relatively hot strip issues from the baking oven, itis cooled to such a temperature that it may be coiled m. 2 is a planview alons' thelinel-I oi'I'ig. 1 H

Fig. 3 is a side ,elevational viewtaken in the direction of the arrows Hin 1111f,v

flgJisadetaiLpartialeleva onal'viewoia bearing mounting for one or theconver s mils in the baking oven, taken axially of theroll;

1'18. 5 is an elevationalview taken from the 113130! FIIJ; v it: Fig. 6is a fragmentsrrperspective view of a portion of the strip steel whichis processed by the apparatus illustrated in Figs. 1 to 3;

Fig. 7 is a view similar to Fig. 1, illustrating a modified, preferredform of the present invention; and,

Fig. 8 is a top plan view of the oven and heating means illustrated inFig. I.

According to one embodiment of the present invention, a coil of stripsteel is disposed adjacent the processing apparatus, and the leading endthereof is first carried through a pre-treatment container which has asuitable cleaner therein for the purpose of removing any grease or dirton the surfaces of the strip. The strip is then carried through a coldwater rinse so as to wash any of the cleaning solution on the surfacesof the strip therefrom and then into a tank or container having therust-proofing solution therein. The strip is then carried through adrying oven and passes from the drying oven onto a spool where it isre-wound into a coil.

Referring to Figs. 1 through 6 of the drawings 7 for a more detaileddescription of one embodiment of the invention, the coil ill of stripsteel I2 is supported on a spool I having a standard It. The strip I2 ispreferably a coil of strip steel which has been cold reduced, boxannealed, and finally temper rolled. The parts forming the processingapparatus may be suitably mounted on a suitable framework, and suchapparatus includes a pre-treatment tank or container I! which may belead lined or constructed of stainless steel, or other acid resistantmaterial for pretreating the strip prior to its treatment in therust-proofing bath.

A housing 20, having a cover 22 associated therewith and provided withan inlet 24 and an outlet 26, is disposed adjacent the tank I! atsubstantially the same level. Cold water rinsing means, includingoppositely disposed pairs.

steel as it is passed between the pairs of pipes.

to wash any pro-treating solution carried by the surfaces of the stripstherefrom. The water is collected in the bottom of the housing and maybe drained therefrom in any suitable way.

Another tank or container 34 is disposed adiaoent the container 2| atsubstantially the same level and is adapted to contain thereintherustpmoflng solution. The rust-proofing solution may be such as thatdisclosed in the McDonald Patent No. 2,030,601, February 11, 1936, andis such that a corrodon resistant, paint holding coating is formed onthe surfaces of the strip of steel as it is passed through the oven. Thesolution may be maintained at substantially room temperature. If it isdesired to raise the tem-. perature, this may be done in any suitableway such as by the immersion of steam or hot water plpesinthebath.

The pie-treatment tank. ll. the rinsing means includes insulated wallsforming the oven enclosure. Suitable doors and 40 may be provided inorder to provide access to the interior I of the oven.

A transversely elongated inlet opening 42 is provided through the bottomwall of the oven 38 immediately above the tank 34 adjacent one side ofthe oven; and a transversely elongated outlet opening 44 is providedthrough the opposite wall adjacent the bottom thereof.

As the strip leaves the rust-proofing tank 34, it passes between a pairof idle rollers 48. The purpose ofsuch rollers is to provide for theeven distribution of the coating solution on the strip and to insurethat excess solution on the strip is not carried into the baking oven.It is a characteristic of the present process that the coating must bethoroughly dried on the strip before it touches any conveying mechanismin order to avoid marking of the strip. Likewise,

excess solution carried along with the strip tends to run and causestreaking. f

According to the broader aspects of the present invention, smoothsurface rollers have been found to be satisfactory, but it has beenfound that for best results such rollers should have a roughened surfacesuch as that disclosed and claimed in the copending application of JohnE. Eckert, SeriaLNo. 319,115, flied concurrently herewith. These rollersengage the strip and serve to control the amount and distribution of therust-proofing solution thereon immediately prior to the entrance of thestrip into the oven, so that the strip is in proper condition for thebaking treatment it receives in the oven. A rustprooflng coating ofsubstantial and uniform thickness is thereby ensured. a

Heating means are associated with the oven and such means include a gasfired air heater 46 which. may be supported on the apparatus' frameworkabove the level of tanks ii and I. An outlet conduit 48 communicateswith the interior of the heater 4. and communicates with the interior ofa fan housing II. The

fan housing is adapted to have a centrifugal fan mounted therein on adrive shaft 52; The drive shaft 2 may be mounted in suitable bearingqandhas a drive pulley I4 assoposedinletconduitsilateachsideoftheonm,

respectively. The conduits I. extend along the sides of the ovenadiaoentthe bottom thereof -andtewiththeinterloroftheovui throughlongitudinally spaced inlet openings 02. Thehotgasesarethusintroduoedintothcoven adjacent the bottom thereof, at each side. and atlongitudinally spaced points.

Outlet openings areprovided through one sidewalloftheovenlladiaemtthetopthereofat longitudinally spaced points andcommunicate II, and 'the 'rust-proo'flng tank 34, are at substantiallythe same level and are aligned in a substantially straight line so thatthe strip of steel may be conveyed into and through each with alongitudinally extending conduit 04 having a downwardly extendingportion M which communicates with the interior of the heater ll.'lhohotgalesmaythuabere-circulatedthmgh wall of the oven 36 andcommunicates with the interior thereof so that the hot gases may bevented from the oven if desired. A damper I is associated with theconduit 66 so as to provide a control for the hot gasesexhausted fromthe oven. The oven is maintained at a temperature of approximately 650F., for example, and the re-circulating conduits, together with theventilating conduit 68, provide an effective and efiicient means forcontrolling the oven temperature along with the controls for the gasheater 46. The inlet and outlet conduits and the heater 46' with thehousing 50 are suitably insulated.

Conveying means are provided for continuously carrying the strip ofsteel through the apparatus so that the intended processing may beeflected and are so operated that the proper time interval for treatmentat each stage is possible. Such conveying means includes a plurality ofdrums or rolls 12, I4, I6, I8, 80, 82, 84, 86, 88, 90, 92, and 94. Thedrums are mounted on shafts which. in turn, are journaled in bearings onthe framework. or. in the case of the oven rolls on' frameworkassociated with the walls of theoven. Certain of the rolls-are drivingrolls and others idle rolls, as will be pointed out hereinafter. Therolls are all constructed with annular flanges 96 at the sides thereof,and the space between the flanges is of substantially the same width asthe width of the strip steel I2. The flanges 96 prevent displacement ofthe strips from the rollers and insure alignment of the strip as it ispassed through the various stages of the process. Rolls 12, 14, I8, and94 are driven rollers, while the remaining rolls are idle guide rollsarranged in a particular manner to be described hereinafter.

In connection with the arrangement of the rolls above described andshown in the drawings, it is pointed out that one of the importantfeatures of this arrangement resides in the position of the roll 82 withrespect to the inlet to the oven. As mentioned above, it is importantthat the rustprooflng solution on the strip be dried before it contactsor engages any of the conveying elesprocket on a drive shaft IOI.extends longitudinally of the apparatus and may be iournalled insuitable bearings at spaced points therealong. Shaft IOI isoperativelyconnected ments disposed within the oven. It will thus be seen that roll82, which is the first of the conveying elements engaged by the strip.is disposed at a position remote from the inlet 42. The roll is thus soarranged that the strip travels a substantial distance within the ovenbefore it engages any of the conveying means, and by the time the stripreaches roll 82, the rust-proofing solution is dried sufliciently thatit will not be injured by its engagement with the roll.

In the above description, it will be noted that the conveying rolls ordrums are provided with flanges 96 in order to prevent displacement ofthe strips from the rollers and to ensure alignment of the strip as itis passed through the various stages of the process. It has been found,however. that the preferred means for attaining this end, that is, theproper alignment of the strip and the prevention of displacement of thestrip from the rolls. is that disclosed in Figs. 4 and 5. This isaccomplished by tilting certain of the conveyor rolls transversely ofthe strip. Preferably, the tlltable rolls will be. the first and lastrolls contacted by the strip during its course through the baking oven.The tilting of the rolls is accomplished by mounting the rolls in themanner described and claimed in the copendlng application of Grant A.Pettit, Serial No. 319,116, filed concurrently herewith.

When the tiltable mounting for the rolls, disclosed in Figs. 4 and 5, isused the rolls having flanges thereon may be used, or smooth rollswithout flanges may be used, as desired.

Referring to Figs. 4 and 5 for a description of this construction, anexemplary mounting for the bearing at one end of the roll 82 isillustrated. The wall of the oven is indicated in broken lines at I28and the shaft I29 of the roll 82 projects through the oven wall asillustrated. The end of shaft I29 has its bearing in an adjustableelement I30, and a seat collar I3I is provided adjacent each end of theshaft to prevent axial movement thereof. A portion of a frame structureis indicated at I32, to which are fixed guide rails I33, in which theelement I30 is mounted for sliding movement. Fixed to the element I30 isa threaded member 134 which passes through a nut I35 mounted in a crossbar I36 fixed to the bottoms of the guide rails I33. It will thus beclear that as the nut I35 is turned. the slide I30 slides with respectto the guideways I33 and thereby vertically shifts that end of shaftI29.

The bearing at the other end of the shaft may be fixed and, since theultimate in upward and downward movement of the bearing I30 will amountto approximately one-half inch, it is sufllcient to prevent binding ifthe fit of.element I30 and the guide rails I33 is relatively loose. Thehearing at the fixed end of the shaft may be given adequate clearance toallow for this small tilting movement. It is to be understood, however,that the bearings at each end of the shaft may beof the self-aligningtype or may be mounted in swiveling mountings.

The driving means for the rolls includes a pr ime mover 96 suitablyconnected by a belt and pulley to a speed reducer 98. The speed reducer98 is connected through a' sprocket chain 99 to a The shaft IOI throughsuitable gear mechanism to feed reduction transmission mechanisms I02,I04, I06, and

' I08. The mechanisms I02, I04, I06, and I08 are operatively connectedto the drive shafts for drums I2, 94, I4, and I8, respectively.

The strip I2 is disposed over the drums I2, I4,

and 94; and so that the strip is frictionally urged against the drumsand may be frictionally driven thereby, a pressure roller H0 isassociated with each one of these drum and engages the upper surface ofthe strip I2 at the top ofeach drum. Each friction roller I I0 isadapted to be mounted to a vertically movable slide member H2 which isslidably disposed within vertical guides II4.

A spiral spring II6 engages'the top of the slide H2 and istelescopically received over the lower end of an adjustable screw 6'which is threadably-received within a threaded mounting member H8. Themember II8 may be fixed to the guideways II4. By adjusting the screws.6'

the pressure exerted by the rollers 0 may be varied J The strip of steelI2 passes over the top of drum I2 and drops into the pre-treating bathwithin container I8. The strip then passes upwardly out of the bath sothat a good portion of the pre-treatingsolution may drain back into thebath, and then passes upwardly over roll 14 and downwardly and underguide roll 16. Roll I8 is disposed at a level above roll I6 so that thestrip I2 passes through the outlet 26 over roll.

16 at an angle upwardly disposed towards the outlet and in so passingwithin the housing 26 passes between the jets of cold water issuing fromthe pipe 26. The jets of cold water impinge against opposite sides ofthe strip l2 and wash any of the pre-treating solution remaining thereonfrom the surfaces of the strip. Due to the inclination of the strip, anywater carried on the surfaces of the strip will drain back into thehousing.

The strip I2 is then passed downwardly under guide roll 66 into andthrough the rust-proofing bath within the container 66. The roller 86 isjournalled in bearings which are slidably mounted within guide membersI26. By vertically adjustlng the position of these bearings, thetautness of the strip I2 may be effectively controlled, and also theinterval of time it remains in the rust-proofing solution.

The strip I2 then passes between the rolls 66, through the inlet 62 intothe oven 66, and in being carried upwardly out of the bath within thecontainer 66 the execs rust-proofing solution will drain back into tank66 below rolls 66.

The strip I2 is then trained over the guide rollers 62, 66, 66, 66, I6,and 62, so that the strip follows a tortuous path within the oven 66 andis thereby subjected to a complete drying operation. Roller 62 isdisposed adjacent the outlet openingus'othatthe strip I2 ispassedthroughthe opening 66 and engages roller 66 with its associated pressure rollerIII to convey the strip from the oven. The strip is then coiled on asuitable spool I22 mounted on standards I26 and at the completion of theprocess such coil may be stored out of doors. Suitable means may beprovided for turning the spool I22 in order to coil the strip.

' Referring to Figs. 7 and 8 of the drawings, the preferred embodimentof the present invention is illustrated. It has been found that theStrip of steel I2, to betreated'accordingtothe present invention, is notfree of dust, grease, dirt, or other foreign material so that it must becleaned prior to treatment in order to accomplish the best results.According to this embodiment of the invention the stripisflrstcleanedbypassingit through analkalibath, then thoroughlyscrub-'bingandrinsingthestripbeforeitispassed through the pro-treatment andfinal treatment baths. Although the alkali bath provides the preferableand most satisfactory cleaning means, other cleaners would besatisfactory. For exam.

' ple, vapor demeans, or an acid cleaner could be used, although it hasbeen fund that good results are obtained with the alkali bath mentionedabove.'"

Also, the material-is at relatively high temperatures. ,The. particularoven temperature used, in order-to obtain'the particular strlptemperature desired depends upon a number of variable factors, such as guge and width of the strip, the coating desiredythe coatingsolutionused, and the length of baking time. The strip according to the presentinvention, adjacent the I52 with a cover portion I56. The tank I62 isadapted to contain an alkali bath I 66 which is preferably maintained ata temperature of degrees to degrees F.

A roll I 58 is suitably mounted within the chamber above the bath andthe strip I2 is adapted to be passed thereover. Rolls I66 and I62 aresuitably mounted and are disposed so that the bottoms thereof extendwithin the bath I66. The strip I2 is then trained'around rolls and I62so that it p through the bath Another roll I66 is mounted above the bathand is located at a level above the roll I66. and the strip I2 is passedtherearound and passes between a pair of wringer rolls I66 which engagethe surface of the strip for a reason to'be pointed out hereinafter.Spray means I66 extend transversely of'the strip I2 and are disposedabove the bath I66 between and adjacent the rolls I62 and I66. Suchmeans I66 may be in the form of tubes having a plurality of smallapertures formed in the wall thereof and may be connected to the bathI66 through suitable conduits with a pumping meanstherewithsothatthealkaliofthebathispumped' I therein. The water in thebath I16 is preferably travels some distance after leaving the ovenbefore it -is re-coiled, but with strips of certainwidthsandthicknessesthereisnotasuillcientreduction in temperaturebetween the time the strip leaves the furnace and thetime-it reaches there-coil reel. It has also-been found that when the strip is coiled attemperatures exceeding approximately 390 1!, therein grave danger ininjuring the coating thereon as the strip is coiled.

maintainedatatemperatureofa v 200 degrees F. Theoover I66 extendsoverthebathiflandthechamberabovethealkaiibath I66 and the chamber above thewater bath I16 areseparated fromeachotherbymeansofa Me or wall I" whichextends' betwem t1 sides ofthechamber enclosingsuch tanks.

Itwillbeseenthattherollslflaredisposed move any of the dirt or alkaliwhich may be.

thereon.

Wringer, rolls I83 are mounted for rotation about horizontal axesadjacent the outlet I80 and engage opposite sides of the strip I2 Justas it leaves the chamber above the water bath so that any excess wateris removed from the surfaces of the strip. r

The, strip I2 is then passed through a pretreatment or flash tank,indicated at I90. Such tank contains a solution I92 whichwill coat the.steel strip. This preliminary coating may be an oxide coating, or othercoating which, when' treated with the final treatment solution, willgive, after baking, a corrosion resistant, paint holding coating on thestrip. A roll I94 is mounted for rotation about a substantiallyhorizontal axis above the bath I92. The roll I94 is so positioned thatthe lower end thereof projects below the surface of the bath at such alocation and to such a depth that the strip I2 is immersed.

in the bath I92 before it contacts roll I94. Both surfaces of the stripare, therefore, wet by the solution I92 before the strip contacts rollI94.

, The strip I2 is trained about the roll I82 and also about the roll I94so that the strip passes into proofing tank 208. The tank 208corresponds to the tank 34 above described and contains a rustprooflngbath 2I0, similar to the bath mentioned above in connection with tank34, or other solution, which when applied over the preliminary coatingwill give a corrosion resistant, paint holding coating on the steelstrip after baking. Rolls 2I2 and 2, corresponding to rolls I8 and 60 inthe embodiment above described are mounted in a similar manner withrespect to tank 34.. The strip I2 is passed around these rolls into andthrough the bath 2 I 0 and passes upwardly therefrom into the bakingoven 2I6.

So that the strip I2 is wiped free of any excess water which is carriedthereon from the rinse chamber 20I, wiper members 2 I8, similar to wiping members I96, are disposed adjacent the outlet 206 in such positionthat they bear against the strip. 7

Rolls 220, similar to the rolls 43 described in the above embodiment,are disposed above the bath 2I0 in a position similar to that describedabove in connection with tank 34 and serve the in the embodimentdescribed above as shown in Fig. 1. The rotating brushes and the wipers,

such as I96, may be suitably mounted on the same framework.

the bath I92 for the pre-treatment effected by this bath. Before thestrip reaches the bath, transversely extending wiper elements I96 aremounted to suitable framework so that they press wainst opposite sidesof the strip and serve to wipe the strip free of any excess waterremaining thereon before the strip passes into the bath.

Such members I96 are formed of such material that they will perform awiping action on the strip without in any way marring the surfacethereof. For example, they may be constructed by wrapping a strong,rugged material, such as canvas, in a plurality of layers about asuitable supporting element, or they may be formed of a strong, ruggedfelt material.

The strip then passes from the tank I90 through an outlet I98 into arinse chamber 20I. Spraying means 202 in the formof tubular membershaving outlet apertures therein are disposed on opposite sides of thestrip I2, transversely thereof, with the openings so positioned thatsprays of water are directed against both sides of the strip. Such spraymeans are placed in communication through suitable conduits, with asource of water, which may be at room temperature, having a pumpingmeans associated therewith so that the spray is in sufficient quantitiesQ and at high enough pressures to accomplish a thorough of the strip.Wiper members 204, similar in'construction to the wiper members I96, aredisposed adjacent the opening I98 and bear against opposite sides of thestrip so as to wipe the major portion of the solution from bath I32 fromthe strip.

The strip is thoroughly rinsed in chamber 2M and it will be seen that itpasses therethrough following anpupwardly inclined path so" that thewater drains back into the chamber 20I. The strip leaves the chamberthrough an outlet 206 and is. then passed into and through the. rust- Adrying oven 222, generally similar to the oven 36 above described, issupported on suitable framework above the rust-proofing tank 208 andincludes insulated walls forming theoven enclosure. Suitable doors areprovided in the oven walls for providing access to the interior thereof.The oven 222 includes an inlet 224, corresponding to the inlet 42, abovedescribed, which is disposed substantially vertically above the pathbetween rolls 220. The oven also has an outlet 225 corresponding to theoutlet above described.

Conveyor rolls 226 and 228 are disposed within the oven and arepreferably mounted therein in the same manner as rolls 82 and 92described above in connection with Figs. 4 and 5. A wall member 230 isdisposed within the oven 222 in spaced relation to the left hand wallthereof (viewing Fig. 7) which extends across the oven 222 to provide avertical conduit 232 which forms an initial drying chamber.

Heating means are associated with the oven and such heating meansinclude a gas fired heater 234 having a burner 236 associated therewith.An outlet conduit 236 communicates with the heater and communicates witha blower housing 240 which has a suitable blower mounted I and 252.

Viewing Fig. 8, it will be seen that the outlet conduits 248 and 250communicate with the drying chamber 232 of the oven on opposite side'sof the strip I2. The outlet 252 communicates with the other portion ofthe oven to the right of wall 230 (viewin'g Fig. 8). An outlet fortheoven is illustrated at 254 and communicates with a return conduit m.The return conduit returnsto the heater 2 for re-circulation of theheated For temperature control, a branch conduit 2" connects the returnconduit 2" and the .inlet conduit 23! and has an adjustable damper 2"associated therewith so that the returned air through the conduit 2" maybe bypassed around the heater 234 in variable amounts directly into theconduit 2", thus affording a simple temperature control means.

From the above. it will be seen that the strip l2 passes directly intothe vertical drying chamber 232 and is trained over the conveyor rolls22! and 228 and then passes out through opening 22'. The heated airenters the conduit 232 adjacent the bottom thereof and passes upwardlyover roll 226 and into the main portion oi the oven.

This heated air is supplemented by the conduit 252 and all of the heatedair then passes out of the oven through outlet 2".

- with this construction it will be evident that thehot gases envelopthe stripas it first enters the oven so that the rust-proofing solutionwill be dried before it reaches the conveyor roll 22!.

This has the advantage pointed out above in detail.

The strip I2, after leaving the oven, is coiled on a suitable spool I22.The spool I22 is driven by suitable means such as a motor 280 connectedto the spool I22 by suitable drive means 2l2. The spool I22, in theembodiment illustratedyis the only driven roller, the remaining rollersabout I of wide width, there is not sufficient time between the time thestrip leaves the oven until it reaches the spool I22 to cool downsuillciently so that it will not be injured during the coilingoperation. To take care of such a contingency, suitable cooling meansare disposed adjacent the coil and blow a cooling medium, such as air,against the strip so as to reduce its temperature to a proper coilingtemperature. Such cooling means may also be in the form of a water orliquid spray disposed at any suitable point between the oven and thespool. One example is illustrated in the form of transversely extendingtubular conduits 210, disposed on opposite sides of the strip and havingapertures therein directed preferably in a direction opposite to that ofthe direction of movement of the strip. tubular members 210 may beconnected to a suitable blower (not shown), so that air is directedagainst the strip. A plurality of such means mayv has -been set tooperate continuously on strip steel as wide. as twenty inches and up to.050 gauge. In this particular apparatus, the-strip is run atapproximately fifteen feet-per minute. Also, in this apparatus the stripis in the scrubber approximately three minutes, .in the pretreatmentsolution approximately thirty seconds.

Such

in the wash tank and. spray approximately thirty seconds, and in thefinal coating solution approx-- imately thirty seconds. The strip thenpasses through the oven in approximately two minutes, the oventemperature being between 600' and 650" F., so th is at appro tely 550F. The immersion coating and baking times which we have given for ourpilot installation have been found to be entirely satisfactory for thegauge and width strip which is being used.

The above-mentioned operation is merely exemplary, and it will beappreciated by those skilled in the art that wider strip steel ofheavier gauges may be used and that the times, speeds, and temperaturesmay be varied within the scope of the present invention. .The strip maybe carried through the apparatus at a much faster rate and the tanks andother processing devices may be sized proportionately to give thedesired treatment times.

It will be evident that by the various embodiments of the inventiondescribed above, simple and efllcient means for rust-proofing stripsteel is provided in which the surfaces oi the strip may be rapidly andeffectively treated. Also, the

structures or the present invention afford means by which strips ofvaried gauge and width may be eflectively treated.

Formal changes may be made in the specific embodiments of the inventiondescribed without departing from the spirit and substance of theinvention, the scope 01'. which is commensurate with the appendedclaims.

What is claimed is:

1. An apparatusfor treating metal strip comprising a series of tankscontaining treating fluids, means for conducting a strip in sequenceinto said tanks. a baking oven, means ior'conducting said strip throughsaid baking oven and pulling means for acting upon the strip upon itsemergence from said baking oven, said oven being arranged above the lasttank of said series and said conducting means being so disposed thereinthat the strip passes from the last tank of said series into said ovenin a vertical path, and traverses substantially the height of said ovenbefore contacting said conducting means and is then generally led in areverse direction to its path through said treating tanks and saidpulling means being disposed in the vicinity oi the entrance of thestrip into the first tank of said series.

2. Apparatus for rust-proofing strip steel comprising a containeradapted to contain a rustprooflng solution, an oven disposed above saidcontainer, said oven having a downwardly presented inlet openingtherein, means for conveying a strip of steel through said container andthrough said inlet opening into said oven, said last namedmeanslncluding a roller element disposed within said oven adjacent thetop thereof, said roller element being so arranged that said strip isdrawn upwardly through said inlet opening and being arranged in aposition remote from said inlet opening, means within said oven adjacentsaid inlet opening forming a drying chamber, heating means associatedwith said oven, and means conducting thehea-ted gases from said heatingmeans to said oven and introducing such gases into said chamber.

3. Apparatus for rust-proofing strip steel comprising a containeradapted to contain a rustprooilng solution, an oven disposed above saidcontainer, said oven having a downwardly prethe strip as it leaves theoven sented inlet opening therein, means for conveying a strip of steelthrough said container and through said inlet opening into said oven,said last named means including a roller element disposed within saidoven adjacent the top thereof, said roller element being so arrangedthat said strip is drawn upwardly through said inlet opening and beingarranged in a position remote from said inlet opening, means within saidoven adjacent said inlet opening forming a drying chamber, heating meansassociated with said oven, and means conducting the heated gases fromsaid heating means to said oven and introducing such gases into saidchamber, said last named means entering said chamber adjacent the lowerend thereof so that said gases pass upwardly through said chamber inenveloping reiationship to said strip.

4. Apparatus for rust-proofing strip steel comprising a plurality of inline containers adapted to contain treating solutions, a drying ovendisposed adjacent the last of said containers, means supplying a heatingmedium to said oven, and conveying means so constructed and arranged asto convey a strip of steel through said containers and through saidoven, said conveyor means including a coiling element about which saidstrip of steel is coiled, said element being disposed at the outlet endof said oven, said coiling element being remotely disposed mpm theoutlet so that said strip will cool down before reaching said element,and cooling means disposed adjacent said element for cooling said strip-7 ROBERT H. GORDON. ROY P. TOOKE.

